Tag Archives: EME

EME QSO from Viêt-Nam

XV9AA told us a little bit more about his activities with Earth-Moon-Earth transmissions. Vu Trong Thu :

“EME communication had always been in my dreams since I learned about it and after our unsuccessful attempts last year.

It is difficult, but there are things that you can do to improve your chance of success and especially thanks to a new software called WSJT developed by Joe Taylor K1JT which
allows the computer to decode very faint signal down to -28 and even -30dB! These together with the fact that I arranged a sked (schedule) with “big gun” stations resulted in successful EME QSOs.

Here’s my conditions: Home station (XV9AA): Moon near perigee (closest to the Earth), about 10 degree above horizon (to maximize ground gain), digital mode JT65B/WSJT, USB mode, 100W output, 144Mhz band, mast-mounted preamp, antenna is 2MCP22 circularized polarization (used for satellite communication) but I disconnected the vertical part and only use the horizontal one (11 elements) for EME.
DX station (KB8RQ): array of 8×4=24 long Yagi antennas, 1.5kW output.

For your information, last week I had another successful EME QSO with RA6AX who probably has the largest VHF amateur radio antenna array of 64 Yagis and 1.5kW output.
His signal peaked at -16dB while mine peaked at -26dB which is well within the capability of WSJT to decode. So I think I can do EME with 50W or even less :)”